Facade flame height ejected from opening of a compartment under the coupling effect of side walls and ambient wind

Abstract

This paper presents an experimental investigation and analysis on the flame height ejected from an opening of fire compartment over the facade under the coupling effect of two side walls and ambient wind normal to the facade. Experiments were carried out in a reduced-scale model consisting of a cubic fire compartment with an opening, a facade wall and two side walls. Side walls were axi-symmetrically placed at the two sides of opening along the facade, while the opening and the facade were set normal to ambient wind generated by a wind tunnel. Facade flame heights were measured for various heat release rates, side wall distances and ambient wind speeds. Results showed that facade flame height increased as side wall distance decreased, meanwhile decreased as wind speed increased. Theoretical analysis was performed to interpret the behavior based on the air entrainment of ejected flame under their coupling effect. A global non-dimensional factor K as a function of side wall distance, ambient wind speed, the two characteristic length scales of opening as well as the dimensionless excess heat release rate was proposed to predict the facade flame height of various conditions. The experimental results were shown to be well represented.